Have you ever wondered why some infants seem to be naturally heavier than others, even though they may not necessarily be eating more? New research is confirming this may have something to do with a baby’s exposure to certain pollutants within the womb.

Research from Spain’s Center for Research in Environmental Epidemiology has confirmed that exposure to certain environmental pollutants in the womb produces a greater incidence of obesity and rapid growth among infants and children.

In the most recent study, the researchers followed over 4,600 infants between 2003 and 2008 who were between the age of six months and fourteen months. Within this population they identified 1,285 children who had experienced rapid growth during their first year and 1,198 overweight babies by the time they were 14 months of age.

During the last trimester of pregnancy the mothers’ blood was collected and analyzed for a number of pollutants, including polychlorinated biphenyls (PCB), dichlorodiphenyldichloroethylene (DDE) and hexachlorobenzene (HCB).

The researchers then collected data relating to the body mass index of each child – measuring that at six months and then again at 14 months.

The researchers found that DDE and HCB were both associated with rapid growth among the infants as well as being overweight at fourteen months.

The researchers concluded:

“Prenatal exposure to DDE and HCB may be associated with early postnatal growth. Further research is needed to evaluate the persistence of these associations at older ages.”

Other research finds similar results for older children

This study confirms an earlier study done by some of the same researchers. This study, however, focused upon children who were older – with an average age of 6.5 years.

This study followed 344 Spanish children between 1997 and 1998, comparing their body mass index at 6.5 years old with their exposure to polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and/or dichlorodiphenyltrichloroethane (DDT) within the womb.

This study again found that the incidence of obesity among the children was significantly higher for those with higher exposures to PCBs and DDE. The increased obesity rate among th